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(1) Field of the Invention
This invention relates generally to latch assemblies, and more particularly, to striker designs for use with latching mechanisms for vehicle doors or other applications.
(2) Description of the Related Art Including Information Disclosed under 37 CFR 1.97 and 37 CFR 1.98.
Motor vehicle door latching mechanisms typically include a handle or electro-mechanically operated latching mechanism mounted on the door, operative to engage a striker mounted on a door post. The latch and striker must remain engaged even under extremely high stress loads as produced by collisions. The National Highway Traffic Safety Administration, Department of Transportation promulgates the Federal Vehicle Safety standards such as Federal Vehicle Safety Standard number 206 covering door locks and door retention components including latches, hinges, and other supporting means, and specifies requirements to minimize the likelihood of occupants being thrown from the vehicle as a result of impact.
In certain types of motor vehicle collisions and crashes, the forces will cause the door to be jammed shut, such as by the swinging end of the door being compressed against the door post, jamming of the latch mechanism against the striker also contributes to the door being stuck in the closed position. This occurs, for example in unibody framed motor vehicles involved in a front or rear end collision. The collision may cause a shortening of the vehicle frame which results in the door striker being forced into the door edge where the latch is mounted, so that the door latch surrounds and is trapped by the door striker, or the lock becomes consumed by the door. In sideways collisions, the door may be extruded behind the door striker by the force of the collision. As a result, the occupants may be trapped inside the vehicle. Injured occupants may not receive necessary or timely medical attention until the door is removed. In the case of an accident where a gasoline line is ruptured or other hazardous material is spilled in the vicinity, an occupant trapped in the vehicle may be exposed to life threatening conditions and be unable to escape.
Certain types of strikers are particularly susceptible to being jammed upon impact. Single bolt style strikers have been widely employed but have been found to be not as strong as stamped designs fastened at two points to the door post. U-bolt style strikers have been widely used, but are prone to trapping a portion of the latch under collision loads. Another striker design used in the industry was a J shaped striker which was bolt mounted to the door post. The J shaped striker was also prone to jamming with the latch mechanism and has only a single fastening point to the door post.
Another striker design is disclosed in U.S. Pat. No. 5,501,495 to Claucherty. This striker is comprised of a pair of individually formed, matched, symmetrical plates. The plates are attached by a spot weld. Additionally, the interior faces of the plates may be brazened. The latch retaining strength of this striker is primarily in the plane of attachment to the door post, and is particularly dependent upon the weld which holds the two halves together. Because the upstanding position of the striker which the latch engages is in a single plane, the striker is consumed by the latch under the compressive force of a collision. This makes it much more difficult to disengage the latch in crash recover. Also, rough edges of the stamped pieces which are welded together do not provide a smooth latching surface for engagement of the latch pawl, resulting in a more difficult operation of the latch.
A need therefore exists for a door striker which provides increased probability of surviving an impact or collision, preferably providing protection in three orthogonal planes and not requiring any welds which may mar the exposed surfaces.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by various structures as covered by the patent claims.
In one embodiment, the invention is a striker assembly comprised of a pair of symmetrically arranged three-plane pieces, including a mounting plate, a striker plate and a back plate. In an alternate embodiment, a symmetrical three-plane striker assembly is formed from a single piece of sheet steel. In the two-piece embodiment, each piece includes a mounting plate, a striker plate including a striker bar and a latch-receiving aperture or throat, and a reinforcing back plate. The mounting plate is configured for mounting the striker assembly to a door post or similar structure. The striker plate has an interior face and an exterior face, and is generally orthogonal to the mounting plate. The striker and mounting plates intersect at generally 90 degrees, and the back plate is generally orthogonal to the mounting and striker plates. In the assembly, the interior faces of the striker plates are placed in surface to surface contact to form a double thickness striker plate and striker bar. The back plate of each piece is generally orthogonal to the mounting and the striker plates. The back plate extends from the mounting plate and is bent along an axis transverse to the mounting plate so that one edge of the back plate intersects the edge of the striker plate opposite the striker bar. The intersecting edge of the back plate may be welded or brazed to the striker plate. The back plate reinforces the entire striker assembly, and prevents the striker assembly from being consumed by the latch in a crash.
Another important aspect of the invention is a cap weld at the contact face of the striker bar. The cap weld bonds the frontal seam of the two striker plates at the striker bar, and provides a smooth radiused surface which facilitates engagement of the latch pawl about the striker bar. In an alternate embodiment, the striker assembly may be comprised of a single stamped piece of sheet steel.
Among the benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description made with reference to the accompanying drawings. The drawings constitute a part of this specification and include exemplary embodiments, and illustrate various objects, features, attributes and mechanical advantages of the invention.